The 3rd Generation Partnership Project (3GPP) has been developing specifications on the Evolved Universal Terrestrial Radio Access Network (E-UTRAN), which includes the Long Term Evolution (LTE) concepts. In RAN2, a Work Item (WI) on enhancements for Diverse Data Applications (eDDA) has been created in Rel-11 to identify and specify mechanisms to enhance the ability of LTE to handle diverse traffic profiles such as social networking applications. The objective of this WI is to identify improvements that increase the network efficiency, extend UE battery lifetime, reduce signaling overhead, and/or enhance user experience and system performance under such traffic loads.
In one scenario within the context of this WI, efficient power consumption is an important characteristic of a mobile device, which is also referred to herein as a User Equipment (UE). One focus area is to change the UE behavior to reduce its power consumption whenever possible. In previous releases of the specification, timers were introduced to enable switching from a connected mode to an idle mode once the timers expire and when there is no data to send. Further, discontinuous reception (DRX) mode was introduced for LTE in 3GPP standards to conserve battery power when the UE remains in the connected mode. There is a wide range of configuration settings available for the DRX parameters that can serve for different types of services, e.g., VoIP, gaming, web browsing, video telephony, etc.
A base station, which is also referred to herein as an eNB, sets various settings for the UE, e.g., the DRX reception mode configuration. There may be scenarios, however, in which the UE has information that is not available at the eNB. Therefore, assistance information provided by the UE to the eNB is considered useful to the eNB. In many scenarios, the UE sends assistance information by sending one or more of a set of predefined values to an eNB. Such assistance information may take the form of a status report, where the predefined values e.g., indicate the priority of a certain service that the UE requests, report certain problems that the UE experiences which the eNB cannot otherwise be aware of, or state the UE's preference for a certain type of connection configuration. The eNB may or may not act upon requests identified by received assistance information. If the eNB decides to act, it will reconfigure the UE connection accordingly. The resulting reconfiguration will be valid until the next connection reconfiguration.
Frequent transmission of such status reports may cause excessive signaling in the network. Avoiding such excessive signaling enables the network to utilize its resources more efficiently, and thus to provide better service. To that end, UE may be restrained from frequent and/or repetitive transmission of the status report. Frequent transmissions may be prevented with a prohibit timer. Repetitive transmissions may be avoided by preventing the UE from sending a status report unless there has been a change to the assistance information.
While such measures effectively reduce the signaling within the network during normal operations, they are not always effective during handover of the UE from a source eNB to a target eNB. Thus, there remains a need for effectively communicating assistance information responsive to a handover decision without increasing the signaling required for such communications.